What factors determine the hardness of TPE raw materials
Source：德创化工Time：2019-11-14Hits：2294
With the more and more extensive application of TPE materials, in recent years, many related enterprises have established themselves at home and abroad. However, many people do not know much about the hardness of TPE and cannot control it, thus causing a lot of troubles. So, how should the hardness of TPE be controlled? Last time I shared with you the shrinkage of TPE, the following technical personnel from Dechuang Chemical Company will share with you how to control the hardness of TPE.
How to control the hardness of TPE:
1. For general TPE, the hardness is adjusted by the content of oil, PP and calcium carbonate. Increase the amount of PP or calcium carbonate, the hardness will increase, otherwise decrease the hardness. Hardness of refueling decreases.
2. If you still have the phenomenon of oil leakage and sticking to your hands when oil filling is normal, it means that the quality of SEBS/SBS material or oil is not good. Of all SEBS materials, Keteng has the best oil filling effect, sometimes it can be filled to 10 times.
3. Oil-filled SBS/SEBS tends to turn yellow. The main reason is that naphthenic oil contains unsaturated double bonds, which turn yellow by oxidation. Generally, Karamay naphthenic oil in China is hydrogenated oil, which will not happen. Therefore, attention should be paid to oil selection.
4, often our products have the following parameters, such as hardness, tensile strength, oil can only reduce hardness and tensile strength, so usually can also add some engineering plastics, such as making TPE often add PP, hardness and strength parameters can be adjusted according to PP and oil filling quantity.
5. Keep rotating or stir-frying as much as possible during oil filling. If the TPE/TPR is easy to agglomerate when standing for oil filling, and the oil filling in each part is uneven, when the oil filling amount is high, the number of revolutions should be reduced, and the filled oil in SEBS/SBS is easy to seep due to high rotating speed (the principle is similar to that of washing machine spin-drying). It is better to leave the oil for a period of time after filling, so that the oil can be fully absorbed by SEBS/SBS before production, otherwise the oil will easily seep during production.
